Grindstone



Nov. 1, 1927. 1,647,722

N. M. BAKER I GRINDSTONE Filed. Nov. 2a. 1925 INVENTOR Ie/mr )IBaken AT RNEY Patented Nov. 1,1927 p Y v I v s ATES PATENT. OFFICE.

MASSACHUSETTS, ASSIGNOR r AMERICA-N 01- UNITED NELSON M. BAKER,

OF SOUTHBBIDGE,

'IIGAL COMPANY OFSOUTHBBIIDGE, TION OF MASSACHUSETTS.

MASSACHUSETTS,

A VOLUNTARY ASSOCIA- enmnsroim.

Application filed November 26, 1923. Serial no. 677,159.

The present invention relates to a floating stone and has particular reference to a stone used in the so-called be'vel -edging machine wherein vaccommodation must be made for the various curvatures for the numerous forms of ophthalmic lenses to be ground.

An important object of provide a fioating'stone of in the stone will be free nally of its drive shaft and means that will drive the regardless of its angle to .to provide driving stone at all times, the said drive shaft.

the invention is to this nature whereto rock longitudiat the same time Another object is to provide a floating stone of this nature that is so mounted that it will accommodate itself to any form and curve' of lens that is to be ground, belng so arranged that an equal amount of glass willbe ground from both taneously.

sides of the lens simul- Other objects and-advantages of the invention will course of the following become apparent during the description.

In the drawings, wherein like numerals are employed to designate like the same,

Figure 1 isa top plan Figure 2 is a vertical taken through one form and Figure 3 is a vertical taken through a slightly the invention.

parts throughout of the invention, transverse section of the. invention,-

transverse section modified form of In the drawings; wherein for the purposes of illustration is shown the bodiment of the invention, ignates the; drive by means of the belt and 6'. Keyed to the the numeral 5 desshaft, which is propelled pulley connection shaft 5 by means of the key 7 is a ball member 8, said shaft 5 passing through a centrally disposed aperture formed in the said ball. The ball member 8' should be of a hardened highly polished material so as to form a good bearing surface.

The stone 9 is carried by the ing means 10, which means has extending 11, which terminates in the semi-spherical or cup shape therefrom the web which has a centrally stone clamp- (1 ball 12 disposed aperture formed as is shown in Figure 2 of the drawings. slightly larger than the The centrally disposed opening'13 is diameter of the'shaft 5 and the face 14 is bevelled to allow for the movement ofthe cup shaped member 12.

The cup shaped member 12 is of a size to rewithin 'ing 24 is seated preferred emceive the ball 8 therein, whereby the ball 8 forms a bearing for the cup to rock upon and as the face 14 is bevelled the cup which carries the clamping member and the stone9, may be rocked sufficiently to allow the stone 9 to accommodate itself to any form of ophthalmic lens. A second cup member or semi-spherical member 15, having the web 16, is clamped to the cupshaped memlrer 12 and the web 11 by the means of the bolts 17. 'It will,.of course, be understood that the cup member 15 is likewise provided with the' centrally disposed aperture 18, while the face 19 is bevelled similar to that of the face 14. The two members thus clamped together 1foorm an adequate socket for the polished all 8.

The drive mechanism for the stone 9 com- 20 which is keyed to the shaft 5 by means of the key 21. -An arm 22, which may be termed as the driver, has the angular extension 23, which is adapted to be received a suitable socket formed in the block '20 in such a .manner that the said driver will at all times rotate with the block 20 and the shaft 5.

prises a block I within the web portions 11 and 16, said bushing being provided with an opening so as to allow of the insertion of the driver 22 therethrough. The curved face 25 islprovided to allow the bushing, which is carried by the stone mounting, to rock upon the-driver in and for the purpose that will be readily understood.

In Figure 3 of the drawings the numeral 26 designates a bearing race-way which is keyed to the drive shaft 6. A stone'27 is carried by the stone clamping means 28, which comprises the web 29, flange 30 and removable ring 31 which is held in place by means of the bolts 32. The web 29 terminates in the bearing race-way 33, and suitable balls 34 are interposed between the 34, which are seated in the depressions 36.

A block 37 is keyed to the shaft 6 adjacent the race-way 26 and supports the driver 38 similar to the driver 22 in Figure 2. The driver 38 is'ada ted to be received through the opening 39 ormed in the web 29, which opening has the curved surface 40 to allow of a rocking movement of the stone and A metallic hardened bushmounting when in use, A jam nut 41 is screw threadedly mounted by means of the threads 42 upon the shaft 6vto clamp the stone when it is desired to hone or true the stone27.

It will be seen that I haye devised an oscillating or floating stone that will readily accommodate itself to all forms and curvatures of ophthalmic lenses when being ground and that driving means are provided that will ensure rotation of the stone no matter how the stone'is rocked upon the shaft 6. In view of the bearing surfaces between, the stationary and oscillatory portions of the mounting, it requires but slight pressure to tilt the stone.

It is therefore to-be understood that the form of my invention herewith shown and described is to be taken as the preferred embodiment of' the same and that various changes in the shape, size and arrangement of parts may be resorted to withoutdeparting from the'spirit of my invention or the scope of the sub-joined claims.

Having thus described my invention,-I claim:

1. In a device of the character described, a drive shaft, a member on the driveshaft having a spherical bearingsurface, an annular grindstone member having a bevelled groove in its periphery, an annular grindstone holding member comprising means for holding the annular grindstone member, spherical bearing means adapted to cooperate with'the bearing member on the shaft so that the grindstone may be laterally.

' 2. In a device of the character described, a

shaft, a ball member secured to the shaft and havinga bearing surface, a grindstone annulus, a grindstone holding annulus comprising means for holding the .grindstone, bearing means to engage the bearing surface of the ball member on the shaft, said annulus having a transverse orifice there through having arcuate bearing surfaces and a driving member secured to the shaft having a finger extending through the orifice in the grindstone holding annulus whereby the grindstone may-be rotated by the shaft and lateral play of the-same allowed through the co-action of the bearing surfaces on the finger and, ball members with the arcuate bearing surfaces in the orifice and the bearmg means in the grindstone holding annulus respectively.

NELSON M.- BAKER. 

